I'm a big fan of SO and the Careers site idea is great.
I have had a profile with Careers for some time, although my profile was only public during the times I was looking for new opportunities (most recently for the last two weeks).
The job market is very hot right now, and I have very marketable skills (mainly MS technologies). I have my resume posted on other sites and get a pretty massive amount of calls/emails on a daily basis. However, I am much more interested in the kinds of companies that would post jobs or search for resumes on a site like this (Joel's Software test, etc.).
I have simply not gotten much response from having my profile public on Careers. This time around (again, the last two weeks) I have yet to be contacted by a company. When I had my profile marked public the last time around, I got contacted twice (and neither a very good match). (Edit: after checking the stats as requested, it was actually 5 times).
I'm not complaining, as this is a free service and (again) I really like the concept. What I'm wondering is if there is something flawed in my profile, if MS technologists are not in particular demand by companies that use Careers (maybe Open Source is more what they are looking for), or if this simply isn't the type of job board that produces a lot of response volume. Maybe fewer responses but higher signal-to-noise ratio?
Edit: maybe a more direct question: do others who use Careers tend to get a fair number of responses, or just occasional responses?